The molecular basis of retinal degeneration in rats suffering from inherited retinal dystrophy (RCS-p/plus strain) is being investigated. Pigment epithelial (PE) cells have been grown in tissue culture. By studying the phagocytosis of rod outer segments (ROS) by normal and dystrophic PE cells, I have shown that the genetic defect in the RCS-p/plus rat is expressed in the pigment epithelium. Experiments are under way to compare protein synthesis by normal and dystrophic PE cells. The molecular architecture of the plasma membrane of both strains of rat is being studied utilizing surface labeling techniques and two dimensional gel electrophoresis.